// 4. 实现类 - 银联支付
package com.example.spi.impl;

import com.example.spi.PaymentService;

public class UnionPayService implements PaymentService {
    @Override
    public void pay(double amount) {
        System.out.println("使用银联支付: " + amount + " 元");
    }
    
    @Override
    public String getPaymentType() {
        return "UnionPay";
    }
}